FIG. 13 shows an article of footwear in the form of a shoe 10 to be worn on a foot of a user with a portion of the shoe 10 cut away so that the inside of the shoe 10 is partially visible. The shoe 10 includes an upper 14 and a sole 18 coupled to the upper 14. The upper 14 covers the top and sides of the user's foot, and the sole 18 covers the bottom of the user's foot and makes contact with the ground. The sole 18 typically includes an insole 22, a midsole 26, and an outsole 30 which cushion and protect the user's foot while the user makes contact with the ground. The insole 22 contacts the user's foot, the outsole 30 contacts the ground, and the midsole 26 is arranged between the insole 22 and the outsole 30. The insole 22 generally provides a comfortable surface for contact with the user's foot and is typically comprised of a thin layer of a man-made material such as, for example, ethylene vinyl acetate (EVA). The midsole 26 generally provides most of the cushioning and shock absorption for the foot of the user and is typically comprised of a polymer such as, for example, polyurethane, surrounding another material such as, for example, a foam, a gel, or recesses filled with air. The outsole 30 generally provides a durable surface which can sustain repeated impact and friction with the ground and is typically comprised of a durable material, such as, for example, carbon rubber or blown rubber.
The sole 18 includes a heel end 34 arranged where a user's heel is positioned when wearing the shoe 10 and a toe end 38 arranged opposite the heel end 34 where the user's toes are positioned when wearing the shoe 10. The sole 18 also includes a medial side 42 arranged closest to the user's center of symmetry when wearing the shoe 10 and a lateral side 46 arranged opposite the medial side 42 farther from the user's center of symmetry when wearing the shoe 10.
Turning now to FIG. 14 and FIG. 15, schematic drawings of a user's foot 50 are shown including a heel 54, toes 56, an arch 58, a medial side 60, and a lateral side 62. FIG. 2 depicts a perspective lateral side view of the bone structure of the foot 50, and FIG. 3 depicts a bottom view of the foot 50 including a plurality of regions located relative to the heel 54, toes 56, arch 58, medial side 60, and lateral side 62. A calcaneus region 66 (shown in FIG. 14) on the bottom of the foot 50 is located substantially beneath a calcaneus bone 68 (shown in FIG. 14) of the user, near the heel 54. A talus region 70 (shown in FIG. 15) on the bottom of the foot 50 is located substantially beneath a talus bone 72 (shown in FIG. 14) of the user, between the heel 54 and the arch 58. A longitudinal arch region 74 (shown in FIG. 15) on the bottom of the foot 50 is located substantially beneath a navicular bone 76, a cuboid bone 78 and cuneiform bones 80 (shown in FIG. 14) of the user, near the arch 58. A metatarsal region 82 (shown in FIG. 15) on the bottom of the foot 50 is located substantially beneath metatarsal bones 84 (shown in FIG. 14) of the user, between the arch 58 and the toes 56. A ball of the foot region 86 (shown in FIG. 15) on the bottom of the foot 50 is located substantially beneath the metatarsal-phalangeal joints 88 and sesamoids 90 (shown in FIG. 14) of the user, between the arch 58 and the toes 56 and closer to the medial side 60 than the lateral side 62. A toe region 92 (shown in FIG. 15) on the bottom of the foot 50 is located substantially beneath phalangeal bones 94 (shown in FIG. 14) of the user, near the toes 56.
When propelling himself on his feet, the user applies different amounts of pressure at different times to the various bones in each foot 50 during what is known as a gait cycle. For example, during a typical walking motion, the gait cycle begins when the user first contacts the ground with the heel 54 of his foot 50, thereby applying pressure to the calcaneus bone 68. As the user shifts his weight forward on his foot 50, he applies less pressure to the calcaneus bone 68 and begins to apply pressure to the talus bone 72, the navicular bone 76, the cuboid bone 78, and the cuneiform bones 80. As the user begins to propel himself off his foot 50, he applies less pressure to the talus bone 72, the navicular bone 76, the cuboid bone 78, and the cuneiform bones 80 and begins to apply pressure to the metatarsal bones 84. As the user propels himself forward, he applies pressure along the metatarsal bones 84 and to the metatarsal-phalangeal joints 88 and sesamoids 90. Finally, as the user begins to toe off and end contact with the ground, he applies less pressure to the metatarsal-phalangeal joints 88 and sesamoids 90 and applies pressure to the phalangeal bones 94. Finally, to toe off, the user applies pressure to the phalangeal bones 94 to propel forward. The user then lifts his foot 50 into a leg swing, and places it down in a location forward relative to where he lifted it. When the user places his foot 50 down again, he first contacts the ground with the heel 54, beginning a new cycle of the walking motion.
Many styles of forward propulsion, including many styles of walking and running, apply a gait cycle substantially similar to that described above. In some styles of forward propulsion, such as, for example, sprinting or shuffling, different amounts of pressure are applied to different portions of the foot 50 for different amounts of time. Additionally, the particular amounts of pressure applied to different portions of the foot 50 can vary from one individual to another. For example, some individuals apply more pressure to the medial side 60 than the lateral side 62 as they progress through the gait cycle. This particular application of pressure is known as pronation. In contrast, some individuals apply more pressure to the lateral side 62 than the medial side 60 as they progress through the gait cycle. This particular application of pressure is known as supination. Additionally, some individuals apply more pressure to their heels 54 when contacting the ground and some contact the ground with a portion of their feet nearer to the arch 58.
Shoes are designed to support and protect the feet of users during gait cycles to provide comfort and to promote efficient propulsion. However, due to differences between individuals in both foot anatomy and personal gait cycle style, some shoes are more comfortable and useful for some users than others. Additionally, producing a shoe configured to meet the variety of needs during all stages of the gait cycle can include producing a large number of different specialized parts which must be assembled into the shoe. Production and assembly of parts are contributing factors to the cost of the shoe. In general, a shoe having a larger number of parts is more expensive to produce than a shoe having a smaller number of parts. In view of the foregoing, it would be advantageous to provide a shoe that is comfortable and useful for a user and that is inexpensive to produce. It would also be advantageous to provide a shoe with a support arrangement that can be easily customized to meet the unique needs of various foot anatomies and individual gait styles. It would be of further advantage if the shoe were configured to provide improved performance qualities for the user, such as improved stability and energy return qualities.